Cloud Applications

When I installed a new LNMP environment on the server today, the system prompts-bash: wgetcommandnotfound during wget. it is obvious that the wget package is not installed. Generally, wget will not be installed by default during minimal installation

/Etc/profile: This file sets the environment information for each user in the system. when the user logs on for the first time, this file is executed. and from/etc/profile. the configuration file in the d directory collects shell settings.

The iptables command can be used to configure Linux packet filtering rules. it is often used to implement firewall and NAT. The configuration of iptables is complex. after mastering the rules, it is not difficult to use iptables to complete the

If you do not know the basic knowledge about IPTABLES, we recommend that you first check it out. configure a filter table firewall. (1) view the settings of IPTABLES on the local machine [root @ tp ~] # Iptables-L-nChainINPUT (policyACCEPT)

It is too cumbersome to configure iptables for several VPS. I saw a script for automatically configuring the iptables firewall in Zhu Ge's LNMP script. I borrowed it and changed it for the people who needed it; only common port settings are provided.

1. objective: to solve the problem of poor intercommunication quality between networks and carriers, connect two linux hosts of different carriers with a dual Nic and perform nat jump through iptablse to solve this problem. 2. main reference

The iptables Port ing settings are as follows: we have a computer with two Nics. eth0 is connected to the Internet, and the ip address is 1.2.3.4; eth1 is connected to the intranet, and the ip address is 192.168.0.1. now we need to forward the IP

Iptables-F // clear rules iptables-AINPUT-ptcp -- dport22-jACCEPT/* allow packets from port 22 into */iptables-AOUTPUT-ptcp -- sport22-mstate -- stateESTABLISHED-jACCEPT/* allow from 22 port entry package return */iptables-AOUT Iptables-F // clear

Command for maintaining the rule table: 1. iptables (-N) to create a new rule table 2. iptables (-X) deletes an empty rule table. iptables (-P) changes the default policy of the built-in rule table. 4. iptables (-L) to list rules in the rule table 5.

The packet filtering firewall uses a software to view the packet header, which determines the fate of the entire package. It may decide to DROP the package, ACCEPT the (ACCEPT) package (let this package pass), or perform other more complex actions.

I have mentioned that the newly purchased server of the company uses CentOS5.5. after deploying Tomcat, I found that I entered 114. 80. *. *: 8080 (ip: 8080), but the default Tomcat homepage cannot be displayed. Because it was previously deployed in

I. iptables command format (more complex) iptables [-ttable] command [chain] [rules] [-jtarget] (1) table ------- specify the table name (raw table, mangle table, nat table, filter table) (2) command ------- chain Operation command (-: append rules (

Today, I saw a very good iptable configuration, which is very detailed. I will repost it and share it with you. learning the firewall configuration under linux will be of great help to improve website security, not to be missed ~ If you do not know

In the past two years, the development of network applications has a high demand for Qos. many companies are doing this. even Xaar has set up a QQos. However, we can see that we still use ports to determine the protocol, they do not have the

Tcpdump is a network packet analysis tool in linux. TcpDump can completely intercept the "header" of the packets transmitted in the network for analysis. It supports filtering network layer, protocol, host, network or port, and provides logical

PF_PACKET registers a Protocol for Packet capture at the system network layer. Then, all outgoing and incoming packets will be transferred to the forward () function. the outgoing direction (outgoing packet) will be used to capture packets in

Tcpdump is a packet analysis tool that intercepts packets on the network according to user definitions. Tcpdump can completely intercept the "header" of the packets transmitted in the network for analysis. It supports filtering network layer,

In Linux, the sniffer includes tcpdump, Nmap, linSniffer, LinuxSniffer, hunt, and sniffit. Next we will only introduce the excellent sniffer in Linux ?? Tcpdump. The installation of tcpdump in Linux is very simple. Generally, there are two

First, enable the kernel forwarding module. Echo1/porc/sys/net/ipv4/ip_forward # This is a temporary practice. it will expire after restart. a good practice is vi/etc/sysctl. modify the net. ipv4.ip _ forward1 and then to make it take effect

Glances allows you to view the most resource projects among similar tools. for details, see: CPU usage memory/SWAP usage system load information kernel statistics and run queue information hard disk read/write data volume network transmission data